For years, aquarium keepers have been telling stories that would seem a better fit in an old pirate’s tale than from a reef tank. These hobbyists have reported elusive and giant worm-like creatures that would attack fish, kill clams, and occasionally wander out into the open to sting aquarium keepers working in the aquarium. These huge worms have the typical bristled look of the commonly found bristleworm, but can reach larger sizes and can pack a nasty punch if they touch the skin. While the normal bristlworms stay small and eat detritus and decaying matter, these giant fireworms worms can attack and kill perfectly healthy aquarium life. Despite their size, these giant worms can go undetected for years, often hiding in the rockwork and usually only coming out at night. When a worm such as this is encountered, the best thing to do is remove it immediately. This video comes from our good friend Clint, a local hobbyist who did just that, remove the monster from the tank as soon it was seen. As for the worm’s disposal, that’s really up to the tank owner. Some aquarium keepers banish the worm to the sump, which is obviously the most humane thing to do, but others inflict a little revenge and kill it.
Update: We previous misidentified this worm as a Eunicid, but a sharp AquaNerd reader pointed out that it was probably a fireworm from the genus Hermodice. After reviewing a high resolution photo of this particular worm, we also came to that conclusion and have updated the text above accordingly.